Worked on the dotnet/orleans repository to enhance observer management by implementing a snapshotting-based ObserverManager in C#. This approach allowed safe handling of concurrent modifications, such as subscriptions and unsubscriptions, during enumeration, addressing common concurrency issues in multi-threaded environments. The solution leveraged asynchronous programming and design patterns to improve thread-safety and reduce runtime risks associated with observer patterns under high-concurrency workloads. Comprehensive unit tests were developed to validate the new concurrent modification behavior and cover edge cases, ensuring reliability and scalability. This work established a robust foundation for future concurrency enhancements and contributed to the maintainability of the codebase.